Miniature electric lamp bulb and socket combination



M y 1940- P. KOLLSMAN MINIATURE ELECTRIC LAMP BULB AND SOCKET COMBINATIION Original Filed 001:. 15, 1957 Patented May .28, 1940 UNITED STATES -MINIATURE ELECTRIC LAMP BULB AND I SOCKET COMBINATIQN Original application October 15, 1937, Serial No. 169,121. Divided and this application May 24, 1939, Serial No. 275,391

3 Claims.

This application is a division of my so-pending application Serial No. 169,121, filed October 15, 1937 which matured into .Patent No. 2,171,431, dated August 29, 1939.

This invention relates to electric illuminating means, more particularly to a lamp, base and socket combination which is particularly adapted for use in an indicating instrument and which permits an easy removal and replacement of the lamp member from the front of the instrument.

In the illumination of indicating instruments, particularly airplane instruments, it has been found convenient to provide a cover glass or sight glass for the instrument, with white paint or difiusing means at the edge of the glass over most of its periphery, and to provide adjacent one point in the periphery, a very small miniature lamp, which, by radiating into the exposed edge of the glass, delivers light to the diifusing means adjacent the edges of the glass cover plate, from which it is thrown onto the scale graduations and pointer.

Great difficulty has, however, been experienced in obtaining a lamp and socket combination which is sufficiently small to avoid interference with the various instruments; which will stay firmly in place in spite of the extreme vibration encountered in airplanes; and which can be readily changed when it burns out, with a minimum of difficulty and a minimum of interference with other instrument parts, and which can be changed easily enough to permit the user to make the change while in flight.

Thus, the problem requires that the lamp shall be extremely small; that it shall be replaceable from the front of the instrument; that it shall be held firmly in place, and that it shall have members which are readily grasped by the operators fingers to remove and replace the lamp.

The present invention provides a socket, a base cooperating therewith and a miniature lamp held therein, which is readily inserted and removed from the front of the instrument into illuminating relationship with the edge of the glass sight window of the instrument.

Thus, an object of the invention is to provide for the removable and replaceable mounting of a miniature incandescent electric light bulb in a socket, through the length of which the bulb passes during the removal and replacement.

A further object of the invention is to pass a miniature lamp bulb through the length of-a supporting socket and to anchor it therein while making electric connection thereto.

u A further object of the invention is to remove PATENT OFFICE and replace a lamp base by manipulation of a finger grip portion while passing the lamp bulb through a supporting socket.

Still a further object of the invention is to pass a lamp bulb through a socket into il1u-- 5. minating position and hold it therein by the interrelationship of contact pins and latch springs.

Still another object of the invention is to pass a lamp bulb through a socket, into illuminating 10 position with respect toan instrument dial, to hold the lamp in illuminating position by the application of a locking member, and to eject the lamp from the socket by a contact spring upon removal of the locking member.

Still a. further object of the invention is to pass a lamp bulb through a socket, lock it therein, and make electric contact thereto through a ferrule adjacent one end of the lamp bulb, znfdb a tip contact at the other end of the lamp 20 Further aims, objects and advantages of this invention will appear from a consideration of the description which follows with accompanying drawing showing for purely illustrative pur- 25 poses embodiments of this invention. It is to be understood, however, that the description is not to be taken in a limiting sense, the scope of this invention being defined in the appended claims.

Referring to the drawing:

Fig. 1 is a side view. in section of an embodiment of this invention;

Fig. 2 is a side view. in section of another embodiment of this invention. 35

In the embodiment shown in Fig. 1, the lamp having aglass bulb l0 enclosing a filament II is provided with a base consisting of a ferrule l2 and a center contact I3. The socket l4 may be made an integral part of an instrument cas- 49 mg IE or it may be attached to the casing by suitable means as shown in the drawing.

The instrument casing shown in the drawing is provided with' a window or cover glass l6 which may be used for distributing light received 5 from the bulb through an aperture I! in the socket and reflected onto indicating means enclosed in the casing by means of a suitable reflector l8 applied to the r of the cover glass or otherwise. The socket provides a passage of 5 larger diameter than the diameter of the bulb into which the lamp is inserted.

The aperture of the socket may be clased by means of a cap member I! secured tothe opening of the socket member in a suitable manner, a

a resilient rim 20 being shown for this purpose in the illustrated embodiment fitting in a snap button manner over the grooved end 2| oi the sleeve of the socket.

A contact spring 22 is provided bearing against the ferrule 12 and connected to a suitable source of current. A center spring 22 is associated with the center contact l3 and connected to the other terminal of the source oi electrical energy.

The lamp is inserted, base first,'into the socket,

thereby compressing the center spring 23. Thecap member l9, having a finger operable grip portion 24, is then secured to the socket and bears with an extended configuration 25 against in Fig. 2 in which corresponding parts are designated by corresponding reference numerals.

In this embodiment, the cap member I9 is of smaller dimensions and provided with a snap ring 28' fitting into a groove in the socket. A sleeve 25 movable against the action of a compression spring 23' in a bore 25 of the socket is provided for connecting the center contact of the lamp in the electrical circuit.

Obviously, the present invention is not restricted to the particular embodiments shown and described. Other forms may be designed without departing from the spirit of the invention.

What is claimed is:

1. The combination of a lamp socket member providing a tubular passage'and having an opening at one end and an aperture at one side for the emission of light; a lamp comprising a filament, a bulb of smaller diameter than said passage, and a tubular base, said lamp being insertable into said passage through said opening into a position in which the filament is adjacent to said aperture; a spring at the bottom of said passage adapted to be distorted by insertion of said lamp; and a cap member having a finger operable grip portion and means ior removably iastening it to the socket member at the said opening of said passage, said cap member having a configuration bearing against said lamp thereby compressing said spring;

2. The combination of a lamp socket member providing a tubular passage and having an openng at one end and an aperture at one side for the emission of light; a lamp comprising a filament, a bulb of smaller diameter than said opening and passage, and a base, said base comprising a ferrule and a center contact, the lamp being insertable through said opening into said passage into a position in which the filament is adjacent to said aperture; a spring at the bottom of said passage adapted to be distorted by insertion of said lamp and forming one socket contact associated with said center contact; a second resilient contact'in said passage associated with said ferrule; and a cap member having a finger operable grip portion and means for removably fastening it to said socket member at the said opening of said passage, said cap member having a configuration bearing against said bulb thereby compressing said spring.

3. The combination of a lamp socket member providing a tubular passage and having an aperture at one side for the emission of light; a lamp comprising a filament, a bulb of smaller diameter than said passage, and a base, said base comprising a ferrule and a center contact, the lamp being insertable into said passage into a position in which the filament is adjacent to said aperture:

. a spring at the bottom of said passage adapted to be distorted by insertion of said lamp and forming one socket contact associated with said center contact; a second resilient contact in said passage associated with said ferrule; and a cap member having a .finger operable grip portion and snap means for removably fastening it to said socket member at the opening of said passage, said cap member having a configuration bearing against said bulb thereby compressing said spring.

. PAUL KOLLSMAN. 

